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23#include <linux/acpi.h>
24#include <linux/completion.h>
25#include <linux/init.h>
26#include <linux/interrupt.h>
27#include <linux/kernel.h>
28#include <linux/module.h>
29#include <linux/slab.h>
30
31#include <linux/of_device.h>
32#include <linux/spi/spi.h>
33#include <linux/tpm.h>
34
35#include "tpm.h"
36#include "tpm_tis_core.h"
37#include "tpm_tis_spi.h"
38
39#define MAX_SPI_FRAMESIZE 64
40
41
42
43
44
45
46
47
48static int tpm_tis_spi_flow_control(struct tpm_tis_spi_phy *phy,
49 struct spi_transfer *spi_xfer)
50{
51 struct spi_message m;
52 int ret, i;
53
54 if ((phy->iobuf[3] & 0x01) == 0) {
55
56 phy->iobuf[0] = 0;
57
58 for (i = 0; i < TPM_RETRY; i++) {
59 spi_xfer->len = 1;
60 spi_message_init(&m);
61 spi_message_add_tail(spi_xfer, &m);
62 ret = spi_sync_locked(phy->spi_device, &m);
63 if (ret < 0)
64 return ret;
65 if (phy->iobuf[0] & 0x01)
66 break;
67 }
68
69 if (i == TPM_RETRY)
70 return -ETIMEDOUT;
71 }
72
73 return 0;
74}
75
76int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
77 u8 *in, const u8 *out)
78{
79 struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
80 int ret = 0;
81 struct spi_message m;
82 struct spi_transfer spi_xfer;
83 u8 transfer_len;
84
85 spi_bus_lock(phy->spi_device->master);
86
87 while (len) {
88 transfer_len = min_t(u16, len, MAX_SPI_FRAMESIZE);
89
90 phy->iobuf[0] = (in ? 0x80 : 0) | (transfer_len - 1);
91 phy->iobuf[1] = 0xd4;
92 phy->iobuf[2] = addr >> 8;
93 phy->iobuf[3] = addr;
94
95 memset(&spi_xfer, 0, sizeof(spi_xfer));
96 spi_xfer.tx_buf = phy->iobuf;
97 spi_xfer.rx_buf = phy->iobuf;
98 spi_xfer.len = 4;
99 spi_xfer.cs_change = 1;
100
101 spi_message_init(&m);
102 spi_message_add_tail(&spi_xfer, &m);
103 ret = spi_sync_locked(phy->spi_device, &m);
104 if (ret < 0)
105 goto exit;
106
107 ret = phy->flow_control(phy, &spi_xfer);
108 if (ret < 0)
109 goto exit;
110
111 spi_xfer.cs_change = 0;
112 spi_xfer.len = transfer_len;
113 spi_xfer.delay.value = 5;
114 spi_xfer.delay.unit = SPI_DELAY_UNIT_USECS;
115
116 if (in) {
117 spi_xfer.tx_buf = NULL;
118 } else if (out) {
119 spi_xfer.rx_buf = NULL;
120 memcpy(phy->iobuf, out, transfer_len);
121 out += transfer_len;
122 }
123
124 spi_message_init(&m);
125 spi_message_add_tail(&spi_xfer, &m);
126 reinit_completion(&phy->ready);
127 ret = spi_sync_locked(phy->spi_device, &m);
128 if (ret < 0)
129 goto exit;
130
131 if (in) {
132 memcpy(in, phy->iobuf, transfer_len);
133 in += transfer_len;
134 }
135
136 len -= transfer_len;
137 }
138
139exit:
140 spi_bus_unlock(phy->spi_device->master);
141 return ret;
142}
143
144static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr,
145 u16 len, u8 *result)
146{
147 return tpm_tis_spi_transfer(data, addr, len, result, NULL);
148}
149
150static int tpm_tis_spi_write_bytes(struct tpm_tis_data *data, u32 addr,
151 u16 len, const u8 *value)
152{
153 return tpm_tis_spi_transfer(data, addr, len, NULL, value);
154}
155
156int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result)
157{
158 __le16 result_le;
159 int rc;
160
161 rc = data->phy_ops->read_bytes(data, addr, sizeof(u16),
162 (u8 *)&result_le);
163 if (!rc)
164 *result = le16_to_cpu(result_le);
165
166 return rc;
167}
168
169int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result)
170{
171 __le32 result_le;
172 int rc;
173
174 rc = data->phy_ops->read_bytes(data, addr, sizeof(u32),
175 (u8 *)&result_le);
176 if (!rc)
177 *result = le32_to_cpu(result_le);
178
179 return rc;
180}
181
182int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value)
183{
184 __le32 value_le;
185 int rc;
186
187 value_le = cpu_to_le32(value);
188 rc = data->phy_ops->write_bytes(data, addr, sizeof(u32),
189 (u8 *)&value_le);
190
191 return rc;
192}
193
194int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy,
195 int irq, const struct tpm_tis_phy_ops *phy_ops)
196{
197 phy->iobuf = devm_kmalloc(&spi->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL);
198 if (!phy->iobuf)
199 return -ENOMEM;
200
201 phy->spi_device = spi;
202
203 return tpm_tis_core_init(&spi->dev, &phy->priv, irq, phy_ops, NULL);
204}
205
206static const struct tpm_tis_phy_ops tpm_spi_phy_ops = {
207 .read_bytes = tpm_tis_spi_read_bytes,
208 .write_bytes = tpm_tis_spi_write_bytes,
209 .read16 = tpm_tis_spi_read16,
210 .read32 = tpm_tis_spi_read32,
211 .write32 = tpm_tis_spi_write32,
212};
213
214static int tpm_tis_spi_probe(struct spi_device *dev)
215{
216 struct tpm_tis_spi_phy *phy;
217 int irq;
218
219 phy = devm_kzalloc(&dev->dev, sizeof(struct tpm_tis_spi_phy),
220 GFP_KERNEL);
221 if (!phy)
222 return -ENOMEM;
223
224 phy->flow_control = tpm_tis_spi_flow_control;
225
226
227 if (dev->irq > 0)
228 irq = dev->irq;
229 else
230 irq = -1;
231
232 init_completion(&phy->ready);
233 return tpm_tis_spi_init(dev, phy, irq, &tpm_spi_phy_ops);
234}
235
236typedef int (*tpm_tis_spi_probe_func)(struct spi_device *);
237
238static int tpm_tis_spi_driver_probe(struct spi_device *spi)
239{
240 const struct spi_device_id *spi_dev_id = spi_get_device_id(spi);
241 tpm_tis_spi_probe_func probe_func;
242
243 probe_func = of_device_get_match_data(&spi->dev);
244 if (!probe_func && spi_dev_id)
245 probe_func = (tpm_tis_spi_probe_func)spi_dev_id->driver_data;
246 if (!probe_func)
247 return -ENODEV;
248
249 return probe_func(spi);
250}
251
252static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_spi_resume);
253
254static int tpm_tis_spi_remove(struct spi_device *dev)
255{
256 struct tpm_chip *chip = spi_get_drvdata(dev);
257
258 tpm_chip_unregister(chip);
259 tpm_tis_remove(chip);
260 return 0;
261}
262
263static const struct spi_device_id tpm_tis_spi_id[] = {
264 { "tpm_tis_spi", (unsigned long)tpm_tis_spi_probe },
265 { "cr50", (unsigned long)cr50_spi_probe },
266 {}
267};
268MODULE_DEVICE_TABLE(spi, tpm_tis_spi_id);
269
270static const struct of_device_id of_tis_spi_match[] = {
271 { .compatible = "st,st33htpm-spi", .data = tpm_tis_spi_probe },
272 { .compatible = "infineon,slb9670", .data = tpm_tis_spi_probe },
273 { .compatible = "tcg,tpm_tis-spi", .data = tpm_tis_spi_probe },
274 { .compatible = "google,cr50", .data = cr50_spi_probe },
275 {}
276};
277MODULE_DEVICE_TABLE(of, of_tis_spi_match);
278
279static const struct acpi_device_id acpi_tis_spi_match[] = {
280 {"SMO0768", 0},
281 {}
282};
283MODULE_DEVICE_TABLE(acpi, acpi_tis_spi_match);
284
285static struct spi_driver tpm_tis_spi_driver = {
286 .driver = {
287 .name = "tpm_tis_spi",
288 .pm = &tpm_tis_pm,
289 .of_match_table = of_match_ptr(of_tis_spi_match),
290 .acpi_match_table = ACPI_PTR(acpi_tis_spi_match),
291 },
292 .probe = tpm_tis_spi_driver_probe,
293 .remove = tpm_tis_spi_remove,
294 .id_table = tpm_tis_spi_id,
295};
296module_spi_driver(tpm_tis_spi_driver);
297
298MODULE_DESCRIPTION("TPM Driver for native SPI access");
299MODULE_LICENSE("GPL");
300
